The objective of the Molecular and Cellular Biology (MCB) Training Program is to provide the highest quality interdisciplinary scientific and academic training in fundamental molecular and cell biology to individuals from diverse backgrounds who will become future leaders in the biomedical sciences. This application is seeking renewal of support for a long-standing successful program. MCB T32 predoctoral students form an integral yet distinct part of the allied BCMB program of Weill Cornell Graduate School of Medical Sciences (WCGS). BCMB is a combined graduate training endeavor of 3 of the 7 programs of study at WCGS: Biochemistry and Structural Biology (BSB), Cell and Developmental Biology (CBG), and Molecular Biology (MB). The WCGS itself is a unique 63-year partnership composed of faculty from Weill Cornell Medical College (WCMC) and the Sloan-Kettering Institute (SKI). The MCB training program includes 80 selected faculty who are members of the BCMB alliance and have a strong collective experience as graduate mentors. Research interests of the MCB faculty are thematically represented by six specific areas, each of which includes world leaders in their field: Cell Structure and Function, Molecular Biochemistry and Biophysics, Nucleic Acid Transactions and Genomic Integrity, Molecular & Cell Biology of Viruses and Microorganisms, Tissue Biology & Development, and Cancer Biology. During their first year, MCB trainees take a Core Curriculum of 5 required courses and 3 laboratory rotations. First year students are closely monitored by their First Year Advisor, who assists them in choosing a thesis mentor at the end of Year 1. During their second year, students must pass the written and oral portions of the ACE (Admission to Candidacy Exam) and form a Special Committee to monitor their thesis progress. In years 1 and 2, all students complete a course in Responsible Conduct of Research, and a Quantitative Biology course focusing on statistics and computational biology. In addition to performing original laboratory research, second year and more senior students enroll in elective courses and `Focus Group' discussion sessions. MCB students are guided by the Training Program Director, attend specially designed Training Program events, and are recommended to be Teaching Assistants in graduate courses. Progress of the MCB trainees is monitored annually with the use of Individual Development Plans. The BCMB Program Directors, 1st year Student Advisors, and Admissions Chair, jointly with the Program Director of the Training Grant, form the Governing Committee of the MCB training program. A separate committee of Senior Advisors provides oversight and evaluation. Currently, the BCMB Program admits an average of 21 students per year on institutional funds provided by WCGS, plus Training Grant funds. The Program has grown in size and quality in recent years, due to the success of our students and new faculty recruitment at both institutions, and it has attracted a significant number of outstanding candidates that are eligible as MCB trainees. We are therefore requesting renewal of this grant, with funding to support a total of 8 predoctoral trainees per year.